Date Utilities

/**
 * Create a new Date instance with fallback to current date
 * @param value - String, Date, number, or null/undefined
 * @returns Valid Date object
 */
function newDate(value?: string | Date | number | null): Date;

/**
 * Parse date string with format and locale support
 * @param value - Date string to parse
 * @param dateFormat - Format string or array of formats
 * @param locale - Locale for parsing
 * @param strictParsing - Whether to use strict parsing
 * @param refDate - Reference date for relative parsing
 * @returns Parsed Date or null if invalid
 */
function parseDate(
  value: string,
  dateFormat: string | string[],
  locale?: Locale,
  strictParsing?: boolean,
  refDate?: Date
): Date | null;

/**
 * Check if value is a Date object
 * @param value - Value to check
 * @returns True if value is Date
 */
function isDate(value: any): value is Date;

/**
 * Check if date is valid and within acceptable range
 * @param date - Date to validate
 * @param minDate - Optional minimum date (defaults to 1/1/1800)
 * @returns True if date is valid
 */
function isValid(date: Date, minDate?: Date): boolean;

/**
 * Set multiple date properties at once
 * @param date - Source date
 * @param values - Object with date properties to set
 * @returns New Date with set properties
 */
function set(date: Date, values: {
  year?: number;
  month?: number;
  date?: number;
  hours?: number;
  minutes?: number;
  seconds?: number;
  milliseconds?: number;
}): Date;

/**
 * Format date with locale support
 * @param date - Date to format
 * @param formatStr - Format string
 * @param locale - Locale for formatting
 * @returns Formatted date string
 */
function formatDate(date: Date, formatStr: string, locale?: Locale): string;

/**
 * Safely format date (handles null/undefined)
 * @param date - Date to format (can be null/undefined)
 * @param options - Formatting options
 * @returns Formatted string or empty string
 */
function safeDateFormat(
  date: Date | null | undefined,
  options: { dateFormat: string | string[]; locale?: Locale }
): string;

/**
 * Format date range with separator
 * @param startDate - Start date
 * @param endDate - End date  
 * @param props - Formatting options with separator
 * @returns Formatted date range string
 */
function safeDateRangeFormat(
  startDate: Date | null | undefined,
  endDate: Date | null | undefined,
  props: {
    dateFormat: string | string[];
    locale?: Locale;
    rangeSeparator?: string;
  }
): string;

/**
 * Format multiple selected dates
 * @param dates - Array of dates
 * @param props - Formatting options
 * @returns Formatted dates string
 */
function safeMultipleDatesFormat(
  dates: Date[],
  props: { dateFormat: string | string[]; locale?: Locale }
): string;

/**
 * Get seconds from date (0-59)
 */
function getSeconds(date: Date): number;

/**
 * Get minutes from date (0-59)
 */
function getMinutes(date: Date): number;

/**
 * Get hours from date (0-23)
 */
function getHours(date: Date): number;

/**
 * Get day of month (1-31)
 */
function getDate(date: Date): number;

/**
 * Get day of week (0-6, Sunday = 0)
 */
function getDay(date: Date): number;

/**
 * Get ISO week number (1-53)
 */
function getWeek(date: Date): number;

/**
 * Get month (0-11, January = 0)
 */
function getMonth(date: Date): number;

/**
 * Get quarter (1-4)
 */
function getQuarter(date: Date): number;

/**
 * Get full year
 */
function getYear(date: Date): number;

/**
 * Get timestamp in milliseconds
 */
function getTime(date: Date): number;

/**
 * Get localized day of week abbreviation
 * @param day - Date object
 * @param locale - Locale for formatting
 * @returns Day abbreviation (e.g., "Mon", "Tue")
 */
function getDayOfWeekCode(day: Date, locale?: Locale): string;

/**
 * Set time components on date
 * @param date - Source date
 * @param time - Time components to set
 * @returns New Date with set time
 */
function setTime(
  date: Date,
  time: { hour?: number; minute?: number; second?: number }
): Date;

/**
 * Set hours (0-23)
 */
function setHours(date: Date, hours: number): Date;

/**
 * Set minutes (0-59)
 */
function setMinutes(date: Date, minutes: number): Date;

/**
 * Set seconds (0-59)
 */
function setSeconds(date: Date, seconds: number): Date;

/**
 * Set month (0-11)
 */
function setMonth(date: Date, month: number): Date;

/**
 * Set quarter (1-4)
 */
function setQuarter(date: Date, quarter: number): Date;

/**
 * Set year
 */
function setYear(date: Date, year: number): Date;

/**
 * Get start of day (00:00:00.000)
 */
function getStartOfDay(date: Date): Date;

/**
 * Get start of week with locale support
 * @param date - Source date
 * @param locale - Locale for week start day
 * @param calendarStartDay - Override for week start day (0-6)
 */
function getStartOfWeek(
  date: Date,
  locale?: Locale,
  calendarStartDay?: number
): Date;

/**
 * Get first day of month
 */
function getStartOfMonth(date: Date): Date;

/**
 * Get first day of year
 */
function getStartOfYear(date: Date): Date;

/**
 * Get first day of quarter
 */
function getStartOfQuarter(date: Date): Date;

/**
 * Get start of today
 */
function getStartOfToday(): Date;

/**
 * Get end of day (23:59:59.999)
 */
function getEndOfDay(date: Date): Date;

/**
 * Get end of week
 */
function getEndOfWeek(date: Date): Date;

/**
 * Get last day of month
 */
function getEndOfMonth(date: Date): Date;

/**
 * Add days to date
 */
function addDays(date: Date, amount: number): Date;

/**
 * Add weeks to date
 */
function addWeeks(date: Date, amount: number): Date;

/**
 * Add months to date
 */
function addMonths(date: Date, amount: number): Date;

/**
 * Add quarters to date
 */
function addQuarters(date: Date, amount: number): Date;

/**
 * Add years to date
 */
function addYears(date: Date, amount: number): Date;

/**
 * Add hours to date
 */
function addHours(date: Date, amount: number): Date;

/**
 * Add minutes to date
 */
function addMinutes(date: Date, amount: number): Date;

/**
 * Add seconds to date
 */
function addSeconds(date: Date, amount: number): Date;

/**
 * Subtract days from date
 */
function subDays(date: Date, amount: number): Date;

/**
 * Subtract weeks from date
 */
function subWeeks(date: Date, amount: number): Date;

/**
 * Subtract months from date
 */
function subMonths(date: Date, amount: number): Date;

/**
 * Subtract quarters from date
 */
function subQuarters(date: Date, amount: number): Date;

/**
 * Subtract years from date
 */
function subYears(date: Date, amount: number): Date;

/**
 * Check if date is after another date
 */
function isAfter(date: Date, dateToCompare: Date): boolean;

/**
 * Check if date is before another date
 */
function isBefore(date: Date, dateToCompare: Date): boolean;

/**
 * Check if dates are equal
 */
function isEqual(date: Date, dateToCompare: Date): boolean;

/**
 * Check if dates are the same day
 */
function isSameDay(date: Date, dateToCompare: Date): boolean;

/**
 * Check if dates are in the same month
 */
function isSameMonth(date: Date, dateToCompare: Date): boolean;

/**
 * Check if dates are in the same year
 */
function isSameYear(date: Date, dateToCompare: Date): boolean;

/**
 * Check if dates are in the same quarter
 */
function isSameQuarter(date: Date, dateToCompare: Date): boolean;

/**
 * Check if day is within date range (inclusive)
 */
function isDayInRange(
  day: Date,
  startDate: Date,
  endDate: Date
): boolean;

/**
 * Check if date is before another with midnight comparison
 */
function isDateBefore(date: Date, dateToCompare: Date): boolean;

/**
 * Check if day should be disabled based on DatePicker props
 * @param day - Date to check
 * @param props - DatePicker props with constraints
 * @returns True if day should be disabled
 */
function isDayDisabled(day: Date, props: {
  minDate?: Date;
  maxDate?: Date;
  excludeDates?: Date[];
  excludeDateIntervals?: Array<{start: Date, end: Date}>;
  includeDates?: Date[];
  includeDateIntervals?: Array<{start: Date, end: Date}>;
  filterDate?: (date: Date) => boolean;
}): boolean;

/**
 * Check if month should be disabled
 */
function isMonthDisabled(month: Date, props: any): boolean;

/**
 * Check if year should be disabled
 */
function isYearDisabled(year: number, props: any): boolean;

/**
 * Check if month is disabled before given date
 */
function monthDisabledBefore(day: Date, props: any): boolean;

/**
 * Check if month is disabled after given date
 */
function monthDisabledAfter(day: Date, props: any): boolean;

/**
 * Check if quarter is disabled before given date
 */
function quarterDisabledBefore(day: Date, props: any): boolean;

/**
 * Check if quarter is disabled after given date
 */
function quarterDisabledAfter(day: Date, props: any): boolean;

/**
 * Check if year is disabled before given date
 */
function yearDisabledBefore(day: Date, props: any): boolean;

/**
 * Check if year is disabled after given date
 */
function yearDisabledAfter(day: Date, props: any): boolean;

/**
 * Check if years are disabled before given date
 */
function yearsDisabledBefore(day: Date, props: any): boolean;

/**
 * Check if years are disabled after given date
 */
function yearsDisabledAfter(day: Date, props: any): boolean;

/**
 * Get effective minimum date considering all constraints
 * @param props - DatePicker props
 * @returns Effective minimum date
 */
function getEffectiveMinDate(props: {
  minDate?: Date;
  includeDates?: Date[];
  includeDateIntervals?: Array<{start: Date, end: Date}>;
}): Date | undefined;

/**
 * Get effective maximum date considering all constraints
 * @param props - DatePicker props
 * @returns Effective maximum date
 */
function getEffectiveMaxDate(props: {
  maxDate?: Date;
  includeDates?: Date[];
  includeDateIntervals?: Array<{start: Date, end: Date}>;
}): Date | undefined;

/**
 * Convert highlight dates array to Map for faster lookup
 * @param highlightDates - Array of dates or HighlightDate objects
 * @returns Map with date keys and HighlightDate values
 */
function getHighLightDaysMap(
  highlightDates?: Array<Date | HighlightDate>
): Map<string, HighlightDate>;

/**
 * Convert holidays array to Map for faster lookup
 * @param holidays - Array of holiday objects
 * @returns Map with date keys and holiday values
 */
function getHolidaysMap(holidays?: Array<{date: Date, holidayName: string}>): Map<string, string>;

/**
 * Add leading zero to single digit numbers
 * @param i - Number to pad
 * @returns Padded string
 */
function addZero(i: number): string;

/**
 * Get range of years for year picker
 * @param date - Current date
 * @param yearItemNumber - Number of years to show
 * @returns Object with start and end years
 */
function getYearsPeriod(
  date: Date,
  yearItemNumber?: number
): { startPeriod: number; endPeriod: number };

/**
 * Get times to inject after specific time
 * @param currentTime - Current time
 * @param currentMultiplier - Time multiplier
 * @param intervals - Time intervals
 * @param injectedTimes - Times to inject
 * @returns Array of times to inject
 */
function timesToInjectAfter(
  currentTime: Date,
  currentMultiplier: number,
  intervals: number,
  injectedTimes: Date[]
): Date[];

import {
  newDate,
  parseDate,
  formatDate,
  addDays,
  isSameDay,
  isAfter,
  getStartOfWeek,
  safeDateFormat
} from "react-datepicker";

// Date creation and parsing
const today = newDate();
const parsedDate = parseDate("2023-12-25", "yyyy-MM-dd", "en");

// Date formatting
const formatted = formatDate(today, "MM/dd/yyyy");
const safeFormatted = safeDateFormat(today, { dateFormat: "PP" });

// Date math
const nextWeek = addDays(today, 7);
const weekStart = getStartOfWeek(today);

// Date comparisons
const isToday = isSameDay(someDate, today);
const isFuture = isAfter(someDate, today);

// Working with date ranges
const isInRange = isDayInRange(checkDate, startDate, endDate);

// Validation
const isValid = isDayDisabled(checkDate, {
  minDate: new Date(),
  excludeDates: [blackoutDate],
  filterDate: (date) => date.getDay() !== 0 // No Sundays
});